Hydroxyproline in the Early Diagnosis of Bone Metastases in Prostatic Cancer

The usefulness of hydroxyproline assays in the early diagnosis of bone metastases was investigated in 26 prostatic cancer patients. Patients with bone metastases detectable by the conventional X-ray technique or by radiostrontium had significantly higher mean serum hydroxyproline values, and they also excreted significantly more hydroxyproline in the urine than the patients without metastases. The patients for whom the external counting with radiostrontium showed metastases, but whose X-ray findings were negative, had elevated serum hydroxyproline values, while the excretion of hydroxyproline and the serum phosphatase concentrations ranged within the normal limits. Patients without metastases had normal serum hydroxyproline values, and their excretion similarly vaned in the normal range. After the introduction of androgen control therapy, the elevated values of hydroxyproline and serum phosphatases became normalized simultaneously over a period of 4 months. The results indicate that serum hydroxyproline a...